I have proof that there is no artificial gravity in Elite!
My screenshot:
Please look at your own holo, and see if has the same feature.
Almost all cars have them, and a little bell sounds when you don't use them.
If you don't use them in your 8+ G fighter aircraft, you will be converted into a very nasty paste, all over the inside of your cockpit.
As you can see, my ugly form is looking for them too...
You don't need seat belts, the remlok suit is locked to the seat, just look at empty seat to see these mechanism.
About walking in ships:
Tiny electromagnetics are built into the soles of shoes to walk over ferromagnetic floors and walkways in ships. The suit has microthrusters for zero-G movement.
ref. Remlok Suits - ED wiki